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Pulse Width Modulation Timer
FEATURES
The Features supported by the PWM are as follows:
•
Five 32-bit Timers.
•
Two 8-bit Clock Prescalers providing first level of division for the PCLK, Five Clock Dividers and
Multiplexers providing second level of division for the Prescaler clock and Two External Clocks.
•
Programmable Clock Select Logic for individual PWM Channels.
•
Four Independent PWM Channels with Programmable Duty Control and Polarity.
•
Static Configuration: PWM is stopped.
•
Dynamic Configuration: PWM is running.
•
Supports Auto-Reload Mode and One-Shot Pulse Mode.
•
Supports for two external inputs to start PWM.
•
Dead Zone Generator on two PWM Outputs.
•
Supports DMA Transfers.
•
Optional Pulse or Level Interrupt Generation.
The PWM has two operation modes:
•
Auto-Reload Mode
Continuous PWM pulses are generated based on programmed duty cycle and polarity.
•
One-Shot Pulse Mode
Only one PWM pulse is generated based on programmed duty cycle and polarity.
To control the functionality of PWM, 18 special function registers are provided. The PWM is a programmable
output, dual clock input AMBA slave module and connects to the Advanced Peripheral Bus (APB). The 18
special function registers within PWM are accessed via APB transactions.
PWM OPERATION
PRESCALER & DIVIDER
An 8-bit prescaler and 3-bit divider makes the following output frequencies:
4-bit divider settings
1/1( PCLK=66Mhz )
1/2 ( PCLK=66Mhz )
1/4 ( PCLK=66Mhz )
1/8 ( PCLK=66Mhz )
1/16 ( PCLK=66Mhz )
Table 32-1: Min. and Max. Resolution based on Prescaler and Clock Divider Values
32-6
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
Minimum resolution
(prescaler=1)
0.030us ( 33.0Mhz )
0.060us ( 16.5Mhz )
0.121us ( 8.25Mhz )
0.242us ( 4.13Mhz )
0.484us ( 2.07Mhz )
S3C6400 RISC MICROPROCESSOR
Maximum resolution
(prescaler=255)
3.87us( 258Khz)
7.75us ( 129Khz )
15.5us ( 64.5Khz )
31.0us ( 32.2Khz )
62.1us ( 16.1Khz )
Maximum interval
(TCNTBn=65535)
0.25s
0.50s
1.02s
2.03s
4.07s
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